ApplicationNo. 06/241595 filed on 03/09/1981
US Classes:152/172, Tire secured152/240, With side anti-skid elements152/242, Securing rings152/243, Modified links59/31, Welding59/34, Holding devicesD12/608Anti-skid device
ExaminersPrimary: Kimlin, Edward C.
Assistant: Bokan, Thomas
Attorney, Agent or Firm
International ClassesB60C 27/06 (20060101)
B60C 27/00 (20060101)
Foreign Application Priority Data1980-03-19 NO
DescriptionThe present invention relates to an anti-skid device for improving the surface grip of a wheel of a vehicle, preventing the vehicle from skidding on a slippery surface. The present invention relates further to a method for manufacturingsuch anti-skid device. The anti-skid device according to the present invention is particularly adapted to pneumatic tires of automotive vehicles and is intended to surround the entire tread face of the tire. The anti-skid device comprises a pluralityof chains which are arranged in substantially parallel approximately zig-zag shaped strands extending longitudinally along the circumference of the tread surface of the tire. The chains are interlinked and linked with supporting side chains runningalong the inner and outer walls of the tire, supporting the anti-skid device on the wheel. The method of manufacturing the anti-skid device comprises production of a plurality of chain lengths, alternatively mounting additional gripping devices on oneside of the chains, whereafter the chains are interconnected. More particularly, but not exclusively, the anti-skid device comprises chain elements which are particularly suited for use on heavy duty vehicles for forestry, mining and construction worksetc.
For anti-skid devices of this type a simple and economical solution from a manufacturing point of view is required, providing sufficient positive engagement between the wheel and the ground surface. Further, sufficient resistance to lateralskidding is required. It should further be appreciated that a solution providing a minimum of metal loss due to splitting of links during the assembly operation is required.
It has previously been proposed to use anti-skid devices formed of chains and arranged in circumferential direction of a wheel to improve the traction of the tire. Two supporting side chains running on each of the tire, supporting transverse orlongitudinally arranged chains, are commonly used. It has further been proposed to interconnect the longitudinally arranged chains by a U-shaped element which is inserted into two adjacent links of the adjacent chains. Upon introduction of the U-shapedlink a yoke is welded to the two free ends of the U-shaped link, thereby securing the position of the two links. According to such a solution, the free end of each leg of the U-shaped link serves as an additional gripping element.
Such type of anti-skid devices provide a minimum of resistance against lateral skidding of the wheel. Further, it should be appreciated that the production of such type of anti-skid devices is dependent upon several complicated and timeconsuming operations such as inserting the U-shaped links into the links of two adjacent chains and subsequently clamp both the two links, the U-shaped interconnecting link and the yoke when welding the yoke to the legs of the U-shaped link. Such methodof production is thus both unpractical and expensive.
The present invention provides an anti-skid device which is particularly adapted for continuous and automatic mass production, in which the required number of steps during assembly is reduced to a minimum. This is achieved by arranging theadjacent chains in a zig-zag pattern on an assembly line and welding the required number of adjacent links together. The length of each chain is adjusted to the length of the circumference of the particular wheel for which the anti-skid device isdesigned, taking into consideration the additional lengths due to the zig-zag pattern. The chains are preferably assembled on a particularly designed mounting jig in the desired pattern. A limited number of adjacent links of two neighbouring chains arethen permanently interlinked by means of welding whereafter the entire anti-skid device upon completion is hardened in any conventional manner. Additional gripping devices may be welded to the individual links of the chains and to the interconnectedpair of links. In the latter case the gripping devices serve the additional purpose of reinforcing the permanent interconnection between the links. In the former case, the gripping devices are preferably welded to one of the two parallel, straightportions of the link, the gripping device being arranged on the side which is intended to be in contact with the ground. The welding of the gripping devices is preferably performed prior to the mounting of the chain(s) on the assembly jig. Each chainlength is preferably given a length which corresponds to the required zig-zag pattern.
The anti-skid device will, due to the zig-zag pattern of the chains and due to the particular arrangement of the gripping devices provide increased lateral stability during traction of the vehicle. This is mainly due to the fact that thegripping device is arranged in an inclined position relative to the direction of travel of the wheel(s), providing a substantial frictional area both in lateral direction of and in the direction of travel of the wheel. From a production point of view itis further a substantial advantage to weld the gripping devices on the links by means of an automatic welding machine prior to the assembly of the anti-skid device. It should further be appreciated that the assembly of the anti-skid device may beautomatized to a large extent since the chain lengths may be assembled on a jig where at least three pair of links may be welded together simultaneously.
By letting the chains extend in the direction of the circumference of the wheel, providing a continuous, longitudinally extending chain pattern, the loss of material due to cutting several chain lengths from a continuous, long chain is reduced toa minimum, mainly since the required number of splitted links is substantially reduced. Further, the additional gripping elements may be welded to the links prior to the cutting of the chain into several chain length, for example by means of anautomatic welding machine.
It should further be appreciated that the anti-skid device according to the present invention provides protection of the tread face of the tire.
The novel features which are considered as characteristic for the invention are set forth inparticular in the appended claims. The invention itself, however, both as to its construction and its method of production, together with additional objects and advantages will be best understood from the following description of a specific embodimentwhen read in connection with the accompanying drawings, in which:
FIG. I shows a section of an anti-skid device in full width, in accordance with the present invention;
FIG. II shows a vertical section through a vertical link seen along line II--II on FIG. I; the link being provided with an additional gripping element;
FIG. III shows a vertical section through a vertical link without an additional gripping element, seen along the line III--III on FIG. I;
FIG. IV shows a vertical longitudinal section through the link shown on FIG. II, seen along the line IV--IV;
FIG. V shows a vertical section through a pair of interwelded links seen along line VV on FIG. I;
FIG. VI shows a horizontal elevation of two interconnected links of two adjacent chain lengths, the interconnected pair being provided with a transversely arranged gripping element welded on to the two links; and
FIG. VII shows a vertical section through the linked pair seen along line VII--VII on FIG. VI.
FIG. I shows in full width a section of an anti-skid device in accordance with the present invention. The anti-skid device comprises twoexternally arranged support chains 1 which, when the anti-skid device is in a fitted position on a wheel, run along the inner and outer walls of the tire. The anti-skid device shown on FIG. I comprises further six centrally arranged chain lengths 2which are intended to extend in a substantial longitudinal direction along the entire tread surface of the tire. The six chain lengths 2 are interconnected and further linked with the two peripherally arranged support chains 1, for example by means ofwelding. Every fourth chain link 3 on adjacent chain lengths 2 are interconnected, providing a zig-zag pattern. According to the present invention each chain length 2 is given a length which exceed the peripheral length of the tire, whereby a patternfor example as shown on FIG. I may be obtained. According to the embodiment shown on FIG. I the links of the chains 2 and 1 are welded together along the parallel portions 4 of each link 3. As shown on the Figures at least some of the vertical links 6of at least one of the centrally arranged chain lengths 2 are provided with gripping elements 5 (cfr. FIG. II) welded to the vertical links 6.
FIG. II shows a vertical section through a vertical link 6 seen along line II--II on FIG. I. The vertical link 6 is on the side intended to be on contact with the ground, equipped with a gripping element 5 welded to the link. The referencenumber 3 denotes a horizontal link.
FIG. III shows a vertical section through a vertical link 6 which is not equipped with a gripping element 5, while FIG. IV shows a vertical, longitudinal section through the vertical link 6 shown on FIG. II, the section is seen along line IV--IVon FIG. II.
FIG. V shows a vertical section through two horizontal links 3 welded together, the section is seen along line V--V on FIG. I. The links 3 are welded together along their common line of contact 7.
In the following one preferred mode of production of an anti-skid device in accordance to the present invention will be described in more details.
The gripping elements 5 are firstly welded in required position on the vertical links of a long, preferably continuous chain line. The welding operation may for example be performed by an automatic welding machine, the chain being continuouslyfed into the welding machine. The chain is then cut into required chain sections 1, 2, the length of which being adjusted to the zig-zag pattern and the peripheral length of the particular tire for which the anti-skid device is designed. The chainlengths 1, 2 are then assembled and arranged in the required pattern on an assembly jig where horizontal links 3 on adjacent chain lengths 1, 2 are welded together for example as shown on FIG. I. The supporting peripheral chains 1 are rigidlyinterconnected with adjacent central chain lengths 2 in a similar manner. Three and three pairs of links 3 may for example be welded together simultaneously. Upon termination of the welding operations of the various pairs of links, the entire anti-skiddevice is hardened in any conventional, suitable manner.
FIG. VI shows a horizontal elevation of two interconnected horizontal links 3 on adjacent chain lengths 2 where for clarity, the remaining links 6, 3 are excluded. The two links 3 are welded together along their common line of contact 7. Agripping element 8 is rigidly fixed to the links 3 by means of welding. The gripping element 8 may for example be formed of a flat bar steel. It should be appreciated, however, that the gripping device may have any suitable profile and that thegripping element 8 not necessarily have to be arranged in a transverse position as shown on the Figure. It should further be appreciated that the gripping element may serve as a reinforcement of the interconnection between the two links.